Stop-off for centrifugal casting molds



Feb. 11, 1936. R. H. EURICH ET AL 2,030,105

STQP'OFF FOR CENTRIFUGAL CASTING MOLDS Filed Nov. 8, 1953 5 Sheets-Sheet 1 I VE/V 7'0 1 R/ch card if Eu 77/671, 521174777 1 FIR/71770 WITNESS BY I HTTORNEY Feb. 11, 1936. H, EURICH ET AL Q 2,030,105

STOP-OFF FOR CENTRIFUGAL CASTING MOLDS Filed Nov. 8, 1933 3 Sheets-Sheet 3 INVENT RG f vV/TNEJS n-r-i'anlver I Patented Feb. 11, 1936 UNITED. STATES STOP-OFF FOR CENTRIFUGAL CASTING MOLDS Richard H. Enrich and Benjamin F. Anthony,

Youngstown, Ohio, assignors to TheYoungstown Sheet and Tube Company, Youngstown, Ohio, a corporation of Ohio Application November 8, 1933, Serial No. 697,094

12 Claims.

This invention relates to centrifugal casting machines for the production of hollow cylindrical ingots by the pouring of molten metal into rotat able molds and is specifically directed to means for stopping off or obstructing the bores of the molds to prevent escape of metal therefrom while in a fluid or semi-fluid state.

' The centrifugal casting of ingots may be carried out either in machines of the single type in which the only movement of the mold during formation of the ingot is one of rotation or in those of the continuous type exemplified by that disclosed in our prior Patent 1,942,919, issued January 9, 1934, and entitled Machine for continuous centrifugal casting, in which the molds are rotated during the pouring of the metal and moved longitudinally as well as rotated during the solidifying period. In both types, some difficulty has been experienced in satisfactorily stopping off the open. end or ends of the molds to prevent difficulties due to splashing and without formation of fins or other projections likely to induce cracks or other defects in the ingots duringcooling.

We are aware that end plates of various types bolted or otherwise rigidly secured to the ends of the molds have heretofore enjoyed extensive use in centrifugal casting of ingots, but devices of this character are frequently difficult to remove from the mold preparatory to 'the stripping operation in the intense heat which renders extremely uncomfortable the close approach of operatives to the molds, particularly when, as often happens, the bolts or other fastening means have been splashed with molten metal during the casting operation which has solidified thereon. It is therefore a principal object of our invention to provide an improved end plate or stop-off mechanism which may be mechanically removed from 40 the mold prior to or during the stripping operation and which renders the close approach of operatives to the mold prior to stripping unnecessary and avoids the difiiculties hitherto encounteredthrough splashing and solidification of the metal on or about the fastenings.

A further object of our invention is to provide an improved stop-off mechanism for molds of th s character embodying means for engagement with the end of the mold and adapted to rotate therewith but which may readily be retracted from the mold after the metal ingot therein has solidified to such an extent that its presence is no longer required.

Another object of the invention in certain of its aspects is to provide stop-off means for molds for centrifugal casting in combination with mechanical means operative to retain an end' plate in stopping-off position with respect to the mold during the pouring and solidifying of the ingot and to retract the end plate fromthe mold when the ingot is to be stripped therefrom.

A still further object of the invention-in some of its forms is to provide an improved removable stop-off for centrifugal molds adapted to be supported: entirely within the mold itself and to be removed therefrom contemporaneously with removal of the ingot; these forms are thus especially intended for use in molds of continuous machines of the character disclosed in our said application.

Another object of the invention is to provide stop-offs for molds for centrifugal casting which may be employed at one end only of each mold, or, if desired, at both ends thereof as when cylindrical molds devoid of integral stop-offs at either end are used. Certain embodiments of the invention, therefore, afford ports through which a pouring spout may be projected for introducing molten metal into the mold and with the aid of which observation of the pouring and inspection of the ingot within the mold are facilitated during rotation of the latter.

Other objects, purposes and advantages of the invention will hereafter more fully appear or will be understood by those skilled in the art from the following description of certain embodiments thereof in which reference will be had to the accompanying somewhat diagrammatic drawings.

Fig. 1 in the drawings is a top plan view partially in section of a centrifugal casting machine of the single type with which one embodiment of our invention is associated; Fig. 2 is a side elevation thereof; Fig. 3 an end view, and Fig. 4 an enlarged fragmentary horizontal section on the lines 4-4 in Fig. 3. Fig.5 is a top plan view of a similar machine partially insection, showing another embodiment of the invention; Figs. 6 and 7 are respectively a side elevation and an end view thereof. Fig. 8 is a view corresponding to Fig. 1 showing our invention in another of its forms, and Figs. 9 and 10 are respective side and end views of the apparatus shown in Fig.. 8; Fig. 11 is an enlarged fragmentary vertical section of the stop-01f employed inthe apparatus shown in Figs. 5 to 10 inclusive disposed in operative relation with the ingot mold and associated parts. Fig. 12 is a longitudinal section of a mold of the type ordinarily used in continuous centrifugal casting machines, provided with stopoffs embodying our invention, and particularly adapted for use in such molds; Fig. 13 is a perspective view of the end stop cover plate employed at the pouring end of the'mold shown in Fig. 12, and Fig. 14 is a similar view of one of the stop-off bodies removed from the mold. Fig. 15 is a view corresponding to Fig. 12 but showing another form of stop-ofi similarly adapted for use in molds for continuous machines, one of the stops being shown in perspective in Fig. 16. In the several figures, like characters are used to designate the same parts.

It will be understood that a casting machine of a usual type is herein shown and described for purposes of illustration only as it forms no part of the present invention; the means employed for rotating and supporting the molds may thus be of any suitable or desired construction adapted for the performance of these functions. The single centrifugal casting machine diagrammatically shown in Figs. 1-4 of the drawings comprises a pair of mold supporting rolls R, R supported and journaled for rotation in antifriction bearings B, B carried by suitable pedestals P, P disposed on the mill floor. The roll R which serves as a driving roll, is provided with an annular flange or guide rib F adjacent one of its ends and, near its mid point, an annular groove or channel'G adapted to receive an endless belt E which passes over the pulley of a driving motor D whereby the roll R and consequently the mold M disposed on the rolls may be H rotated at a suitable speed for centrifugal cast- The mold M comprises a hollow cylindrical body provided with a circumferential groove K in its outer surface adapted to receive the flange F to prevent longitudinal movement of the mold with respect to the rolls when disposed thereon. One end of the mold shown in the drawings is formed with an inwardly directed annular flange L which serves as a stop for the pouring end of the mold and provides a port S through, which a pouring spout (not shown) may be projected for introducing molten metal into the interior of the mold. The opposite end of the mold is open and, in the example shown, is provided with a rabbet or groove I adapted to receive a portion of the stop-off mechanism of our invention.

This mechanism as shown in Figs. 1 to 4 comprises a circular end plate 2 having a step or groove 3 cut in its outer edge to bring the circumferential portion of the front face of the end plate into conformity with the mold end whereby a fairly snug fit is obtained and the front face 4 01 the plate thus forms a complete end closure for the mold when in operative position as shown in Fig. 4. The end plate, which is adapted for rotation with the mold, is supported from its center on a shaft 5 threaded into the plate and carried in antifrietion bearings 6 housed in cylinder 1 closed at one end. The cylinder" lidably supported in a sleeve 8 integral with a pedestal 9 ,disposed on the mill floor adjacent the open end of the mold, anda stepped ring l0, secured to the outer face of the plate by bolts ll, overlies a radial flange l2 on the adjacent open end of the cylinder to maintain the plate in assembled relation with the cylinder, although not in sufficiently tight engagement to prevent its free rotation with respect thereto on its supporting shaft 5.

An actuating cylinder l5 having a piston (not shown) connected to a piston rod I6, is disposed in axial alignment with cylinder 1, the piston being adapted for longitudinal reciprocation in cylinder [5 under the influence of compressed air or other suitable fluid admitted on one side or other thereof through pipes I 8, I9 by means of which the piston may be advanced or retracted as desired. The piston rod I6 extends forwardly from the actuating cylinder and is threaded into and secured to the head or closed end of the cylinder 1 by a lock nut 20 whereby reciprocation of the piston in the actuating cylinder correspondingly moves cylinder 1 and hence the end plate, permitting the latter to be mechanically retracted from the end of the mold or moved up into engagement therewith as desired.

When ingots are to be made in the apparatus just described, the end plate is desirably held in position to effectively stop off or close the bore of the mold and prevent escape of metal therefrom by pressure of actuating fluid entering the actuating cylinder through pipe l9. Rotation of the roll R, and hence of the mold M and the end plate, is then initiated by means of the motor D or whatever other mechanism is provided for this purpose, the end plate being firmly but rota-tably held in engagement with the mold by the mechanism just described. The pouring spout (not shown) is then projected into the mold through the port S and the desired quantity of molten metal introduced into the interior of the mold, after which the pouring spout is retracted. Rotation of the mold is continued, however, until the ingot formed by the molten metal has partially or wholly solidified or at least has reached a state such that further rotation is unnecessary. Sometime during or after solidification of the ingot, the end plate is retracted through reverse operation of the piston in cylinder IS, the valves controlling the fluid pipes l8, [9 being readily manipulated to pro duce this result, and the mold is then removed from the rolls R, R and transported to a stripping station or otherwise disposed of, while a new mold, or the same one after the stripping of the ingot therefrom, is thereafter placed in the same position on the rolls and the operation is repeated.

In the form of the invention shown in Figs. 5 to 11 inclusive, substantially similar casting machines are utilized but the molds M employed therein are not provided with the rabbet or groove I utilized in the end of mold M. However, the end stop employed in the machine shown in Figs. 5 to 7 comprises a face plate 22 which may conveniently be made of cast iron,

and provided with a rabbet 23 adapted to fit snugly against the inner edge of the open end of the mold. There is preferably a central bore -24 through the face plate and the latter thus provides in effect an annulus disposed within the mold integral with a larger annulusoverlying its end. A disk 25, desirably formed of sheet metal of sufficiently heavy gauge and provided with a central opening 26, is disposed in axial alignment with the plate 22 and is preferably fairly tightly fitted within the mold bore just inside said plate for rotation with the latter and the mold during the casting operation.

The mechanical means which we provide in this form of the invention for maintaining the face plate in operative engagement with the mold end during the casting operation comprises an arm 28 supported from a horizontal shaft 29 carried by bearings 30 disposed on the mill floor ad- .iacent its ends and adapted to permit pivotal movement of the arm through an arc of approximately 90 about the shaft. The arm is shaft 29' supported in bearings 30 attached to provided with an enlarged substantially circular head 3land a bore 32 adapted to align with bore 24 in the face plate, and is'secured to the shaft by means of a key 33 for rotation therewith. A slotted pitman 34 is also keyed to the shaft at a point remote from the arm for connection with reciprocating means whereby shaft 29 is rotated to move the arm into or out of operative position with respect to.the mold. Said means comprise an actuating cylinder 35 in which a piston rod 36 is reciprocated under the influence of fluid pressure acting upon a piston in the cylinder. The outer end of the piston rod is provided with a bearing support 31 and a yoke 38 integral with the rod, carries a pin 39 which extends through the slot in the pitman 34, and constrains the latter to .move in correspondence with reciprocation of the piston rod. Thus, when a suitable fluid under pressure is introduced into cylinder 35 to effect reciprocation of the piston and piston rod, arm 28 is correspondingly moved from the position shown in full lines in Fig. 6 to that shown in dotted lines in said figure or vice versa, the dotted lines indicating the position occupied during stripping of the ingot from the mold, and while the face plate is shown disposed thereon, it will be understood that this is for convenience only as it is preferably not in any way secured thereto. However, when the sheet metal disk 25, the plate 22, the arm 28 and associated mechanisms are disposed as indicated in Fig. 5, the disk engages the .mold fairly tightly, and thus may readily rotate therewith when rotation of the mold is initiated while the arm forms a substantial and rigid backing for the face plate and the disk to prevent their being forced from the end of the mold by the fluid metal when introduced thereinto through the pouring port S at the opposite end thereof. While this operation is being performed, it may readily be observed through the aligned openings in the disk, face plate and the arm, or, if desired, they may be used as the sole or as a supplemental port particularly, of course, when the end stop of our invention is used at each end of an open mold.

After the mold has been charged and the ingot formed therein has solidified sufiiciently, the arm 28, usually carrying the face plate 22 along with it, may be moved to the dotted line position shown in Fig. 6 by suitable operation of the actuating mechanism. The disk is retained in the mold in engagement with the end of the ingot as it generally adheres rather closely thereto and the ingot may now be stripped from the mold without removing the latter from the machine since the arm 28 has been withdrawn from alignment therewith and from the path of the ingot as it leaves the mold. However, if desired, the mold and its contained irqgot may be removed bodily from the machine and an empty mold disposed on the rolls in its place. In either case, a new disk 25 is fitted to the mold, the face plate is positioned therein, and the arm 28 brepght up to hold the latter in place, after which-the casting operations are repeated.

the invention just described. Thus, the pivot the floor of the mill, provides a center about which the arm 28 may rotate, and a connecting rod 40 pivotally secured to. the arm 28 is operated by a pitman 4| on a shaft 42 projecting from a gear reducing mechanism 43. The latter is operated by a motor 65 which is thus effective through the linkage described to move the arm 28' about its pivot 29' through an arc whose limits are indicated by the full and dotted line positions respectively shown in Fig. 10.v Thus, in operation of this form of the invention after the disk 25 and the face plate 22 have been manually positioned in the mold and the head 3| of the arm 28' brought into engagement with the rear face of the face plate was to align the head therewith and prevent its axial displacement, rotation of the mold and hence of the disk and the face plate may be initiated and the casting effected, after completion of which the arm may be retracted for stripping of the ingot by suitable actuation of the motor 45.

As indicated in Fig. 11, a fairly close fit and firm and solid support for the rear of the sheet metal disk is afforded by the face plate which is in turn firmly backed up and supportedby the non-rotating head of the adjacent pivoted arm. Moreover, the aligned central bores-in the disk, face plate and the head provide a convenient port for observation of the pouring or which may be used as a supplemental or alternative pouring port if desired.

While in the foregoing description we have referred to the use of but one end stop mechanism in a casting machine, illustrating and describing molds provided with integral end stops 'at one end of each, we have done so for convenience only as it will be apparent by mere duplication of our improved end stops they could be employed for stopping off both ends of molds devoid of integral end stops. However, the form of the invention shown in Figs. 1 to 4 inclusive would not be adapted for this purpose inasmuch 4 as that end of the mold to which it is applied is entirely closed, and when this form is used at one end of a mold open at both ends, one of the end stops shown in Figs. to may conveniently be used at the other as each of them provides openings through which a pouring spout may be introduced into the mold.

Similarly, the forms of our invention shown in Figs. 12 to 16, now to be described, may be utilized in the molds of single casting machines either at one end of a mold provided at its other end with one of the end stops hereinbeforedescribed or alone, as in the open end of a mold provided with one integral end stop. We prefer, however, to use these forms of the invention in plain cylindrical molds devoid of end stops such as are usually associated with continuous machines, and they will therefore be described with neference thereto, more especially since their interchangeability is, of course, merely a matter of choice By reference to our aforementioned application, the casting of ingots in continuous machines using open molds will be readily understood and it is believed no extended description thereof will be necessary to the full comprehension of our present invention now to be described.

Thus, in Fig. 1.2, the open mold M" comprises a hollow cylindrical body having its central bore open at both ends and provided with annular grooves 48 spaced a short distance inwardly from the said ends. The stop-off of our invention adapted for use in a mold of this type and shown in Figs. 12-14, comprises a heavy metal annulus 49 whose outside diameter is very slightly less than that of the bore of the mold. The annulus is provided with a groove 59 in its exterior surface of suitable depth to loosely receive a split spring locking ring 5| to permit the latter to be slightly compressed therein when the body is being inserted into the mold bore. The ring 5| is normally of slightly larger diameter than the annulus when in an uncompressed state so that after compression and insertion into the mold the ring expands and partially enters the groove 48 when it becomes aligned therewith. Prior to the positioning of these stop-offs in the respective ends of the mold, we preferably insert a shield in each end to assist in stopping-off the metal and prevent it from directly contacting the stop-offs themselves. These shields may be identical if both ends are used for pouring but if, as is usual, but one end only is so used, the disk at that end preferably comprises a cylinder 53 whose outer diameter is less than the inner diameter of the stop-off annulus and thus adapted to fit loosely therein, while a radial flange 54 having its edge beveled as at 55 and of diameter such that it fits snugly in the mold bore, projects from the inner end of the cylinder and overlies the inner face of the stop-01f annulus when assembled therewith in the mold. The shield at the opposite end of the mold may then comprise merely an annular sheet metal plate 56 having its outer edge similarly beveled as at 51 and snugly fitting within the bore of the mold in engagement with the other stop-01f annulus, the central opening in the disk permitting observation of the pouring and the insertion of stripping mechanism after completion of the casting and setting of the ingot. These shields will usually adhere to the cast ingot after it is stripped from the mold, and as they may be manufactured relatively cheaply, it is usually desirable to provide a new set for each mold preparatory to casting, although the stop-offs themselves may be re-used indefinitely. By suitably proportioning the axial length of the annulus inwardly of the groove 50 corresponding variation in the lengths of the ingots can be readily effected.

The stop-offs shown in Figs. 15 and 16 also are adapted for use with open molds, particularly those devoid of the grooves which are provided in the mold just described. These stopoifs may thus be positioned in any desired spaced relation from the ends of the mold corresponding to ingots of varying lengths to be cast. The stop-off employed at the pouring end of the mold shown in Fig. 15 preferably comprises a split opens toward the interior of the mold and extends radially across the face of the ring when the latter is in operative position in the mold and in which the molten metal may run during casting, the shape of the groove readily permitting removal of the ring from the cast ingot.

The stop-off utilized at' the opposite end of the mold and disposed therein at a. proper distance to provide for the casting of an ingot of the desired length may be identical with the ring 60 or, if preferred, as when casting-chamfered end ingots for pilgering, an annular ring- 63 embodying theprinciples of stop-oils before described but modified in 'that'one inner edge of this i is angularly beveled as at 64 to provide substantial support for a shield 65.consisting of a strip of sheet metal of the proper shape formed into a truncated cone having overlapping ends 66, 61 and thus fitting into the conical recess formed by the tapered face 84 of the ring 63. The absence of any fastening or securing means between the ends of the strip permits the truncated conical shield 65 to expand and tightly engage the tapered walls of the ring 63 and also engage the mold bore with its edge, when, during the casting operation, centrifugal force of the metal within the mold and bearing against the shield forces the latter outwardly from the mold axis in all directions. The shield thus eilectually prevents escape of molten metal between its edge and the adjacent mold wall and a well formed chamfer is produced on the end of the ingot substantially without any projecting fins which -might interfere with or render diflicult subsequent pilgering operationsu It will be understood that the stop-ofis shown in Figs. 15 and 16 inclusive are desirably so formed and arranged as to permit their positioning in the mold .bore at any desired distance from itsends whereby the necessity of providing molds of different lengths for the casting of ingots of various lengths is eliminated; a like result may be attained with a stop-oil of the .form shown in Figs. 12 and 14 by employing a spring ring of substantially rectangular instead of round cross section seating in a correspondingly formed groove in the annulus and of suihcient size and resiliency to hold the annulus at any desired point in the mold bore by yielding engagement with its wall, or even by providing the annulus with radially directed spring pressed plungers instead of a spring ring.

While we have herein shown and described certain embodimentsof our invention adapted for use in single type centrifugal casting machines and other embodiments adapted for use in continuous machines of the type disclosed in our said application, Serial No. 6l2,611, we do not intend or desire that our invention shall thereby be in any way limited or confined by or within this disclosure, since the latter is for the purpose of imparting to those skilled in the art the nature, principles and characteristics of the invention and is thus illustrative only; changes and modifications in the form and arrangement of the several parts and in details of construction thereof will therefore readily occur to those skilled in.the art in applying our invention to any specific type of mold or machine, either similar to or different from those herein shown and described, and may be made if desired without departing from the spirit and scope of the invention as defined in the appended claims.

Having thus described our invention, we claim and desire to protect by Letters Patent of the United States:

1. In combination with a centrifugal casting machine comprising a mold having a cylindrical bore open at one of its ends and means for rotating the mold, an annular sheet metal disk disposed in said bore adjacent its open end, means extending into the end of the mold and axially aligned therewith to afford axial support for said disk, and reciprocating means movable into and out of alignment with the bore operative to mainadjacent said end, movable into and of align tain said last mentioned means in said alignment' while the mold is rotating.

2. In combination with a centrifugal casting machine comprising a mold having a cylindrical bore open at one of its ends and means for ro tating the mold, an annular sheet metal disk disposed in said bore adjacent its open end, means disposed adjacent the end of the mold and axially aligned therewith ,to aiford axial support for said disk, and means operable while the mold is rotating to move said last mentioned means out of alignment with the mold.

3eIn combination with a centrifugal casting -machlne comprising a mold havinga cylindrical bore open at one of its ends and means for rotating the mold,tan annular sheet metal disk disposed in the bore adjacent its open .end and adapted to rotate with the mold, an annular face plate disposed in the bore outwardly of said disk operative to afford axial support thereto, and

means for maintaining ,the face plate in opera-.

tive relatively movable engagement with th mold during its rotation.

4. In combination with acentrifugal casting machine comprising a mold having a cylindrical boreopen at one of its ends and means for rotating the mold, an annular sheet metal disk disposed in: the bore adjacent its open. end and adapted to rotate with the mold, an annular face plate'extending into the bore outwardly of said disk, and mechanical means operable to retract said face plate from alignment with the mold while it is rotating.

5. A stop-oiffor a centrifugal mold having a' cylindrical bore open at one of its ends and an annular groove in the bore adjacent said end, comprising an annular metal body disposed in said bore in alignment with said groove, said body having an annular groove in its periphery, and a split spring ring interposed between said body and the moldand extending into both grooves.

6. A stop-off for a centrifugal mold having a cylindrical bore open at one of its ends ,and an annular groove in the bore adjacent said end, comprising an annular metal body disposed in said' bore in alignment with said groove, said body having an annular groove in its periphery,

a split spring ring interposed between said body and the mold and extending into both grooves, and a substantially fiat annular sheet metal shield disposed in alignment with said body on the. opposite side thereof from the adjacent end of the mold and having a beveled circumferential edge adapted to engage the mold wall.

7. End stop mechanism for molds for centrifugal casting comprising a metal plate engaging an endrof the mold,.and a pivoted arm disposed ment with the 'mold. and adapted to engage and support said plate, said arm and plate having aligned openings forming a passage communicating with the mold bore.

8. A stop-off for a centrifugal mold comprising an annular body of 'metal adapted to engage the mold wall, said body'being split to permit slight compression and having a substantially V-shaped groove extending radially -'of one face thereof,

one wall of the groove being continuouswith one of the split surfaces of said ring and the other.

wall thereof being continuous with the other split surface thereof whereby the width of said groove is varied in correspondence with compression on the Y 9. In combination with an ingot mold adapted for the .centrifugalcasting of hollow ingots and having a cylindrical bore, a removable stop-ofl seated in said bore and comprising spring means exerting radial pressure on its wall to thereby maintain the stop-off in place during the pouring of the metal.

10. In combination with a centrifugal casting mold, an annular sheet metal disk seated in the mold bore for contact by the metal when poured,

said disk having a flat central part and its outer marginal edge curved from the plane of said part and beveled at its periphery to thereby insure intimate engagement between the disk and the wall of the bore.

- 11'. In combination [with a centrifuga mold having a cylindrical bore open at one end, an annular sheet metal disk seated in and peripherally engaging the mold bore for contact by the fluid metal when poured into the mold, and means for 'with' respect to the disk removably seated in the i mold bore in heat exchanging relation with that face of the disk remote from the 'metal throughoutan area not materially less than the area of contact of the metalwith. the opposite face of the disk RICHARD H. EURICHI BENJAMIN F. ANTHONY. 

